Fluid-pressure-reducing valve.



PATENTED JUNE 28, 1904.

. No. 763,375. I

F. L. DODGSON.

FLUID PRESSURE REDUCING VALVE.

APPLICATION FILED OCT. 25,1901.

no MODEL.

\NITNESEEE 4 0. mf /4% 7: W-

. or low pressure.

trolled.

V UNITED STATES Patented June as. 1904.

PATENT OFFICE.

FRANK L. DODGSON, OF ROCHESTER, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO PNEUMATIC SIGNAL COMPANY, OF ROCHESTER,

NEW YORK, A CORPORATION OF NEW YORK.

FLUlD-PRESSUFiE-REDUCING VALVE.

SPECIFICATION forming part of Letters Patent No. 763,375, dated June 28, 1904;. Application filed October 25, 1901. Serial ITO- 79,943. (No model.)

To all whom it may concern:

Be it known that I, FRANK L. DODGSON, a citizen of the United States, and a resident of Rochester, in the county of Monroe and State of NewYork, have invented certain new and useful Improvements in Fluid Pressure-Red ucing Valves,of which the following is a specification. i Q

This invention relates to a reducingvalve for reducipgfluid-pressure, and especially airpressure, in a pipe-line to supply another line at a lower pressure.

The invention is described with reference to the accompanying drawings, in which Figure 1 shows a vertical longitudinal section of the valve, and Fig. 2 shows a plan view of the same.

The valve-casing 1 has an inlet-chamber 2. The inlet-pipe conveying the fluid-pressure which is to be reduced is designated by p and connects with the chamber 2, as shown. An outlet-chamber 3 in the casing is connected to the outlet-pipe 4:, which conveys the reduced The two chambers are separated bya suitable valve-seat 5, upon which seats the valve-block 6, whereby communication between the inlet and the outlet is con- A spring 7 normally tends to close the valve 6 upon its seat. The valve-block 6 is guided in an extension 8, projecting into the chamber 2, so that its walls are free from the outer casing of the valve. A port 9 through this cylindrical extension forms communication between the chambers 2 and 3 when the valve-block is away from its seat. A cover 10 closes the valve-casing at the top and forms an abutment for the spring 7. The valve-block 6 has a stem 11 loosely fitting and guided in a cylindrical extension 12 of a plate 13. This extension 12 is itself loosely guided in a corresponding aperture a of the valvecasing. The bottom of the valve-casing is closed by a flexible diaphragm 14, which may be of rubber or any other suitable flexible material and upon which the plate 13 rests. In the base of the valve-casing is formed a diaphragm-chamber 15, which connects with chamber 3 and the outlet through a port 16.

is below the predetermined point.

The diaphragm 14 is held between a flange b on the base of the valve-casing and a flange 0 on the bottom extension-piece 17. In this extension-piece a plate 18, corresponding to the plate 13, is guided by means of a hollow cylindrical extension 19 of said plate 18. The diaphragm 14 is between the two plates 13 and 18. A regulating-spring 20, whose pressure may be adjusted by means of a bottom cap 21, screwed into the extension-piece 17 :tends to resist the downward motion of the diaphragm and of the plate 18 and constitutes an adjustable resistance on one side of the diaphragm. The spring 20 is stronger than the spring 7 and tends to open the valve 6.

The operation of this reducing-valve is as follows: It is supposed that the valve-block 6 under the influence of the spring 20 is slightly away from its seat, so that air or fluid from the high-pressure supply 19 can enter the chamber 3 through the chamber 2 and the port 9. The spring 20 is so regulated that this opening of the valve will be so small that the pressure in the chamber 3 is reduced, and this reduced pressure will act, through the port 16 and the chamber 15, upon the upper surface of the diaphragm 14:, thus tending to counteract the effect of theIspring 20 and to allow the spring 7, assisted by the fluid-pressure on the top of the valve 6, to close said valve. By proper adjustment .of the spring 20 these opposingtendencies of the fluid-pressure and of the spring can be so-regulatedthat the valve will be opened to a degree just sufficient to allow the desired pressure to pass through as long or as soon as the pressure in the outlet Should the pressure in the chamber 3 become too great, the result will be that the pressure in the chamber 15 and on the top of the diaphragm is likewise increased, causing the balance of pressures existing between the upper and lower springs and the fluid in the chamber 2 to be destroyed and allowing the valve 6 to close freely upon itsseat, shutting oflf the air-supply to the chamber 3 entirely as soon as pressure inthe outlet rises above the predetermined point and until a sufficient reduction of pressure has taken place to cause the spring 20 to open the valve again.

The diaphragm-plates 13 and 18 are guided by the respective extensions 12 and 19, which fit in guideways in the casing, so that each plate cannot tilt. but moves only in a straight path in the line of movement of the valve, and thus the tendency to tilt the valve is obviated and the valve cannot stick or jam in its movements and fits accurately on its seat. So, too, by setting the valve-stem 11 in the extension 12 the same effects are aided.

The purpose of the cylindrical extension 8 is to avoid condensation in case moist air is the fluid used and consequent possible deterioration of the valve-seat by the formation of ice upon it. The valve-seat and the valve are entirely within the bore of said cylindrical extension, and both the inner and the outer walls of this extension are always at the same temperature, because the bore of the valve-casing is filled with air coming from the supply and this air is both outside of and inside of the extension 8. As there is no difference of temperature, there can therefore be no condensation of the moisture which may be carried by the air, and the valve-seat is thus protected. All condensation will take place on the inner wall of the valve-casing 1.

An important feature of the construction is the fact that the stem 11 of the valve-block is not rigidly attached to the diaphragm nor to the plate 13 upon it, but is acted upon by said diaphragm in an upward direction only. The valve will thus close upon its seat as soon as excess of pressure in the chamber 3, and therefore in the chamber 15, has depress. l the diaphragm to a suflicient extent, and it n be held to its seat by the uniform pressure of the spring 7 and the air upon its upper surface. Any fluctuation of the diaphragm below the closing-point will not aifect the valve. If, on the other hand, the stem 11 were rigid with the diaphragm, the valve would hover around its closing position, seating upon its seat with greater or less pressure in correspondence with every slight variation ofthe position of said diaphragm. This would produce the objectionable hammering of the valve upon its seat, commonly called chattering. By the construction shown this chattering is entirely done away with. Another important point is that the valve is rendered more sensitive, as it is either held to its seat by the full effective pressure or is quite free from it. It cannot be closed under a varying pressure, as is the case in those constructions wherein the diaphragm and valve are in one piece and every pulsation of the diaphragm is rigidly transmitted. The diaphragm acts substantially as would a piston in a cylinder forced downwardly by air-pressure transmitted through a port, such as 16, and lifted by a spring, such as 20. In the present example of my invention the diaphragm and its regulating-spring are active only to hold the valve open and not to close it. The seating of the valve is done independently and positively by the upper spring and by the air-pressure as soon as the diaphragm has been sutficiently depressed to release said valve.

What I claim is- 1. In a fluid-pressure-reducing valve, the combination of a valve-casing having a highpressure inlet and a low-pressure outlet, a valve controlling the communication between said inlet and outlet, a spring for closing said valve, a stronger spring for opening said valve, means for regulating the tension of the latter spring, a diaphragm-chamber in said casing, a flexible diaphragm adapted to act upon said stronger spring, a diaphragm-plate, means for guiding said diaphragm-plate to move only in the line of movement of said valve, and a port connection from said lowpressure outlet to said diaphragm-chamber, whereby the valve closes when pressure in the outlet upon the diaphragm is sufficient to compress the stronger spring, and the valve is opened by said stronger spring when pressure in the outlet falls below a predetermined pressure, substantially as described.

2. In a fluid pressure reducing valve, a valve-casing having a high-pressure inlet and a low-pressure outlet, a valve controlling the communication between said inlet and outlet, a spring for closing said valve, a stronger spring for opening said valve, a flexible diaphragm adapted when under pressure to compress said stronger spring, a diaphragmchamher in said casing, a port connection from said outlet to said diaphragm-chamber for conveying pressure to the diaphragm, a plate upon .saiddiaphragm having an extension provided with a socket, a guide-aperture in the valvecasing fitting said extension, and a stem extending from said valve and resting loosely in said socket, substantially as described.

3. In a fluid-pressure-reducing valve, a

valve-casing having a high-pressure inlet and a low-pressure outlet, a valve controlling the communication between said inlet and outlet, a spring for closing said valve, a stronger spring for opening said valve, a flexible diaphragm adapted when under pressure to compress said stronger spring, a diaphragm-chamber in said casing, a port connection from. said outlet to said diaphragm-chamber, a plate upon said diaphragm having an extension provided with a socket, a guide-aperture in the valvecasing fitting said extension, a stem extending from said valve and resting loosely in said socket, asupplementary casing containing said stronger spring, and a cap adapted to screw into said casing and to regulate the tension of said stronger spring, substantially as described.

4. In a fluid pressure reducing valve, the combination of a valve-casing having a highpressure inlet and a low-pressure outlet, a

valve for controlling the communication between said inlet and said outlet and having a valve-block, an extension having Walls free from the outer casing of the valve in which said valve-block moves, an air-chamber connected with the inlet and surrounding said extension, a spring for closing said valve, a stronger spring for openingsaid valve, means for regulating the tension of the latter spring, a diaphragm-chamber in said casing, a flexible diaphragm adapted to act upon said stronger spring, and a port connection from said lowpressure outlet to said diaphragm-chamber, whereby the valve closes when pressure in the outlet upon the diaphragm is suificient to compress the stronger spring, and the valve is opened by said stronger spring when pressure in the outlet falls below a predetermined pressure, substantially as described.

5. In a fluid -pressure-reducing valve, the combination of a high-pressure supply, a lowpressure outlet, a valve for controlling communication between the supply and the outlet, a flexible diaphragm, a diaphragm-plate,

a guide contiguous to said diaphragm-plate for guiding said diaphragm-plate to move only in the line of movement of the valve, an adjustable resistance on one side of said diaphragm, a chamber communicating with the low-pressu re outlet on the other side of said diaphragm, and means interposed between this diaphragm and the valve for opening said valve positively under the influence of the diaphragm as soon as pressure falls below the predetermined point in the'outlet, but allowing the valve to close freely under the high pressure Without being affected-by the further fluctuations of the diaphragm as soon as pressure in the low-pressu re outlet rises above the predetermined point, substantially as described.

FRANK L. DODGSON.

Witnesses:

O. M. PERKINS, F. BISSELL. 

